The present disclosure herein relates to a holographic display apparatus and a method for driving the same, and more particularly, to a holographic display apparatus with reduced switching errors and a method for driving the same.
Recently, researches on stereoscopic (three dimensional) images and image reproduction technology have been carried out. A typical two-dimensional imaging system provides a planar image, but a three-dimensional imaging system which is a type of an imaging technology presents actual image information of an object to an observer.
A spatial light modulator (SLM) for producing a hologram image may be manufactured using a silicon substrate or a glass substrate. As a required size of a hologram image is increased, a technology for manufacturing an SLM using a glass substrate is being developed. A pitch between pixels of an SLM may be reduced to obtain a hologram image with a wide viewing angle.
As the pitch between pixels are reduced to secure a viewing angle, the pitch between pixels (e.g., 5 μm) may become even smaller than a pitch between pads (e.g., 12 μm) which enables a chip on glass (COG) process in which a driver driving chip is directly attached to a substrate of an SLM. In this case, it may be difficult to perform the COG process.
In order to secure the pitch between pads which enables attachment of a driver driving chip, an SLM may be driven in a time-shared manner by integrating a switching element with the SLM. In order to reduce resistance of the switching element used for the time-shared driving, a channel width of the switching element may be increased. As the channel width of the switching element is increased, a parasitic load between a gate electrode and a source electrode of the switching element and a parasitic load between the gate electrode and a drain electrode of the switching element may increase. The parasitic loads of the switching element may cause a switching error which interrupts accurate transfer of a data voltage according to a size ratio of parasitic loads of data lines determined by a size and resolution of an SLM.
Therefore, an SLM to be manufactured on a glass substrate requires not only the switching element for the time-shared driving but also a technical solution for reducing switching errors to accurately transfer a data voltage.